got accused of stealing Criminal Records, Expungement

My friend cousin was accused of stealing some food worth around $ 5 . He got stopped by the LPO and no police was called. I heard that the LPO only took down his information from his driver license and took a picture of him. He was told he is now banned from this particular store and the LPO didn't make him sign anything. However, the LPO told him he will be receiving some letters from the company . I have helped him to do some researched and I know he should be receiving some civil demand letters. Will he also receive a SOME KIND OF " NON TREssPASSING " Agreement that he needs to sign ?! If he SIGN the NON TREssPASSING agreement ?! does it mean HE IS ADMITTED to GUILT ?! Please help him. He is a great person/ student... We also heard of some kind of National Thief database. If he sign the NON TREssPASSING agreement ?! does it mean he is admitted to GUILT and he will be put on that list which will prevent him getting a job most retail chains ... He didn't know much when he got stopped by the LPO. He just wanted to get it over with when it happened. THE LPO did not make him sign anything at the store !